Bone is a living tissue comprising a number of constituents including calcium carbonate, calcium phosphate, collagen and water and is continuously being replenished by resorption and deposition of bone matrix.
When a bone fractures the usual treatment is to reposition the fractured bone back into place, to stabilise the position of the bone, and then to wait for the bone healing process to occur. Bone healing is a complex process which is generally regarded as involving three phases: reactive phase, reparative phase and remodelling phase.
During the reactive phase a haematoma forms at the fracture site and inflammatory cells and fibroblasts infiltrate the bone under prostaglandin mediation. This results in the formation of granulation tissue, ingrowth of vascular tissue, and migration of mesenchymal cells. During the reparative phase, fibroblasts begin to lay down stroma that helps support vascular ingrowth. As vascular ingrowth progresses, a collagen matrix is laid down while osteoid is secreted and subsequently mineralised, which leads to the formation of a soft callus (cartilage) around the repair site. After a period of time from weeks to months the cartilage ossifies, forming a bridge of woven bone between the fracture fragments. During the remodelling phase the healing bone is restored to its original shape, structure, and mechanical strength. The remodelling phase occurs slowly over months to years, however, adequate bone strength is typically achieved in three to six months.
The healing of bone fractures is clearly a lengthy process. Notably, cartilage, unlike other connective tissues, does not contain blood vessels and therefore compared to other connective tissues, grows and repairs more slowly. Further, bone healing can be delayed or impaired when any of the healing processes do not function property or in a timely manner. This can be both a major setback to the individual and a costly clinical problem. Accordingly, approaches that speed up the body's natural process of regenerating bone and cartilage are clearly advantageous.
The present inventors have surprisingly found that plant extracts disclosed herein and compositions comprising same, promote bone and cartilage repair by inducing new bone formation and new cartilage growth.